Add Inner Ring code

pkg/core/object/header.go

@@ -0,0 +1,73 @@
+package object
+
+import (
+	"errors"
+)
+
+// Header represents NeoFS object header.
+type Header struct {
+	// SystemHeader is an obligatory part of any object header.
+	// It is used to set the identity and basic parameters of
+	// the object.
+	//
+	// Header must inherit all the methods of SystemHeader,
+	// so the SystemHeader is embedded in Header.
+	SystemHeader
+
+	extendedHeaders []ExtendedHeader // extended headers
+}
+
+// ErrNilHeader is returned by functions that expect
+// a non-nil Header pointer, but received nil.
+var ErrNilHeader = errors.New("object header is nil")
+
+// ExtendedHeaders returns the extended headers of header.
+//
+// Changing the result is unsafe and affects the header.
+// In order to prevent state mutations, use CopyExtendedHeaders.
+func (h *Header) ExtendedHeaders() []ExtendedHeader {
+	return h.extendedHeaders
+}
+
+// CopyExtendedHeaders returns the copy of extended headers.
+//
+// Changing the result is safe and does not affect the header.
+//
+// Returns nil if header is nil.
+func CopyExtendedHeaders(h *Header) []ExtendedHeader {
+	if h == nil {
+		return nil
+	}
+
+	res := make([]ExtendedHeader, len(h.extendedHeaders))
+
+	copy(res, h.extendedHeaders)
+
+	return res
+}
+
+// SetExtendedHeaders sets the extended headers of the header.
+//
+// Subsequent changing the source slice is unsafe and affects
+// the header. In order to prevent state mutations, use
+// SetExtendedHeadersCopy.
+func (h *Header) SetExtendedHeaders(v []ExtendedHeader) {
+	h.extendedHeaders = v
+}
+
+// SetExtendedHeadersCopy copies extended headers and sets the copy
+// as the object extended headers.
+//
+// Subsequent changing the source slice is safe and does not affect
+// the header.
+//
+// SetExtendedHeadersCopy does nothing if Header is nil.
+func SetExtendedHeadersCopy(h *Header, hs []ExtendedHeader) {
+	if h == nil {
+		return
+	}
+
+	h.extendedHeaders = make([]ExtendedHeader, len(hs))
+
+	copy(h.extendedHeaders, hs)
+}